After a sustained period of possession inside the Hamilton half, Rotorua fullback Selesitino Ravutaumada hit a gap about 40m out.
He passed inside to centre Hayze Perham who drew the last man and found halfback Jayden Sargeant on his inside shoulder.
Sargeant was rewarded for some great support play with a try under the sticks.
The try was converted by first five-eighth Quinn Collard and Rotorua led 7-3.
However, the lead only lasted 10 minutes as Hamilton worked their way inside the Rotorua 22.
They showed great patience as the forwards kept the ball in hand and took turns charging at the try line.
Eventually it was Hamilton number eight Tevita Fa'ukafa who bulldozed his way over to give his side the lead. The try was converted and Hamilton took a 10-7 lead into half time.
Hamilton started the second half strongly.
After a scrum inside the Rotorua 22 Hamilton spread the ball left and created a simple overlap for winger Emoni Narawa to dive over in the corner. The try was converted and Hamilton led 17-7 with 25 minutes to go.
They extended their lead minutes later after their forwards made good metres up the middle. Hamilton then spread the ball left and that man Narawa was over in the corner again.
Coby Miln struck his second successive conversion from the left-hand sideline in a superb display of kicking, to extend Hamilton's lead to 24-7.
Hamilton continued to dominate territory and possession and in the 53rd minute kicked a penalty from right out in front to lead 27-7.
The pressure on Rotorua began to show late in the game as, desperate to get back into it, they produced momentum-breaking errors at crucial times.
With 10 minutes to go Hamilton had another converted try as second five-eighth and captain Quinn Tupaea broke two tackles in the middle of the field to dive over next to the posts.
After the game Rotorua coach Ruki Tupuna said his side got bullied.
"They were bigger, stronger and tougher.
"We need to toughen up a little bit, even if you're smaller you can be relatively tough about what you're doing.
"We knew what was coming, we knew they'd come out strong, they're a physical team but if we could stop their go-forward we'd be okay.
"We knew what we had to do and we just weren't able to do it," said Tupuna.
With a straight final between the top two teams at the end of the season, picking up the win today could turn out to be crucial for Hamilton come the pointy end of the season.
Secondary school results:
Super 8:
Tauranga Boys' College 34 v Napier Boys' High School 26
Rotorua Boys' High School 7 v Hamilton Boys' High School 34
Division 1:
Rotorua Boys' High School II 31 v John Paul College 31
Trident High School v Te Whare Kura o Mauao win by default
Opotiki College 0 v Western Heights High School 48
Aquinas College 15 v Bethlehem College 20
Division 2:
Otumoetai College 12 vs Rotorua Boys' High School III 12
Tauranga Boys' College III 0 vs Taupo Nui A Tia College 46
Whakatane High School 0 vs Te Puke High School 57
Tauhara College 47 vs Papamoa College 7
Division 3:
Reporoa/John Paul College 10 vs Rotorua Lakes High School 19
Rotorua Boys' High School U15A 18 vs Mount Maunganui College 11
Tarawera College - Bye
